<!DOCTYPE html>
<html>
<head>
	<title>id</title>
	<style type="text/css">
		.app {
			width: 200px;
			height: 200px;
			margin: 10px 10px;
			display: block;
			background: red;
		}
	</style>
</head>
<body>
<button class="btn">开启动画</button>
<div class="app">
</div>
</body>
<script src="../jQuery/jQuery-3.4.1.js"></script>
<script type="text/javascript">

$(function() {
	$('.btn').click(function() {
		$('.app').animate({
			width: '400px',
			height: '400px',
			margin: '50px 400px'
		}, 2000);
	})
})

</script>
</html>